Robot, method and program of controlling robot

ABSTRACT

A robot may include a driving control unit configured to control a driving of a movable unit that is connected movably to a body unit, a voice generating unit configured to generate a voice, and a voice output unit configured to output the voice, which has been generated by the voice generating unit. The voice generating unit may correct the voice, which is generated, based on a bearing of the movable unit, which is controlled by the driving control unit, to the body unit.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to a robot that corrects anoutput voice based on a bearing of a head unit of the robot, and amethod and a program of controlling the robot.

Priority is claimed on Japanese Patent Application No. 2010-056265,filed Mar. 12, 2010, the content of which is incorporated herein byreference.

2. Description of the Related Art

All patents, patent applications, patent publications, scientificarticles, and the like, which will hereinafter be cited or identified inthe present application, will hereby be incorporated by reference intheir entirety in order to describe more fully the state of the art towhich the present invention pertains.

In recent years, there has been performed an art in which informationother than a language such as a prosody and emotion information isattached to an output voice of a communication robot. By attaching theprosody or the emotion information to the output voice, the meaning ofthe output voice can be transmitted more accurately. Japanese UnexaminedPatent Application, First Publication No. 2002-23775 discloses a methodof modeling a vocal tract of a man so as to increase the expressivepower in a voice synthesis.

In the prior art described above, the output voice is not changed evenif the bearing of the communication robot, especially in the directionof the face of the communication robot, is changed, which can seemstrange to people.

SUMMARY

A robot may include a driving control unit configured to control adriving of a movable unit that is connected movably to a body unit, avoice generating unit configured to generate a voice, and a voice outputunit configured to output the voice, which has been generated by thevoice generating unit. The voice generating unit may correct the voice,which is generated, based on a bearing of the movable unit, which iscontrolled by the driving control unit, to the body unit.

The movable unit may include a head unit, and the voice generating unitmay correct the voice, which is generated using a vocal tract filter,based on the bearing in a direction of a pitch axis of the head unit.

The voice generating unit may use the vocal tract filter, whichamplifies a frequency band of a signal of the voice, a sound pressurelevel is based on a pitch angle that corresponds to the bearing of thehead unit in the frequency band. The voice generating unit may amplifythe frequency band, which is based on the pitch angle, of the signal ofthe voice, which is generated, using the vocal tract filter.

The movable unit may include a head unit. The voice generating unit maycorrect a left-right ratio of an output level of the voice, which isgenerated, based on the bearing in a direction of a yaw axis of the headunit.

The voice generating unit may correct a left-right ratio of an outputlevel of the voice, which is generated, based on the bearing in adirection of a yaw axis of the head unit.

A method of controlling a robot may include controlling of a driving ofa movable unit that is connected movably to a body unit, generating of avoice, and outputting of the voice, which has been generated. Thegenerating of the voice may include correcting of the voice based on abearing of the movable unit to the body unit.

A program may control a robot including a movable unit that is connectedmovably to a body unit, the robot generating and outputting a voice. Theprogram may execute a driving control step of controlling a driving ofthe movable unit, a voice generating step of generating the voice, and avoice output step of outputting the voice, which has been generated bythe voice generating step. The voice generating step may correct thevoice, which is generated, based on a bearing of the movable unit, whichis controlled by the driving control step, to the body unit.

BRIEF DESCRIPTION OF THE DRAWINGS

The above features and advantages of the present invention will be moreapparent from the following description of certain preferred embodimentstaken in conjunction with the accompanying drawings, in which:

FIG. 1A is a front elevation view illustrating a robot in accordancewith a preferred embodiment of the present invention;

FIG. 1B is a side elevation view illustrating the robot of FIG. 1A;

FIG. 2 is a block diagram illustrating a configuration of the robot ofFIG. 1A;

FIG. 3A is a graph explaining a content related to a correction by avoice signal correction unit of the robot of FIG. 1A;

FIG. 3B is a graph explaining a content related to the correction by thevoice signal correction unit of the robot of FIG. 1A;

FIG. 3C is a view explaining a content related to the correction by thevoice signal correction unit of the robot of FIG. 1A;

FIG. 4 is a view explaining the correction by the voice signalcorrection unit of the robot of FIG. 1A.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention provides an art by which a natural sounding voice,which does not seem strange to people, can be output based on a bearingof a robot.

In the robot of the present invention, a voice output unit does notoutput a voice that has been generated by a voice generating unitwithout change. The voice that has been generated by the voicegenerating unit is corrected based on a bearing of a movable unit to beoutput from the voice output unit. Therefore, the robot can output anatural sounding voice, which does not seem strange to people, based onthe bearing of the movable unit without moving a position and an angleof a speaker based on the bearing of the movable unit.

In the robot of the present invention, the voice is varied based on thebearing of a head unit in a vertical direction by imitating a variationof a voice by a man. Therefore, the robot can output a more naturalsounding voice.

In the robot of the present invention, a frequency band that depends ona variation of a pitch angle is changed. Therefore, the robot can outputthe voice effectively.

In the robot of the present invention, the voice is varied based on thebearing of the head unit in a horizontal direction. Therefore, the robotcan output a more natural sounding voice.

By using a method and program of the present invention, an effectsimilar to the robot of the present invention can be acquired.

The present invention will be now described herein with reference toillustrative embodiments. Those skilled in the art will recognize thatmany alternative embodiments can be accomplished using the teaching ofthe present invention and that the present invention is not limited tothe embodiments illustrated for explanatory purpose.

FIG. 1A is a front elevation view illustrating a robot 4 in accordancewith a preferred embodiment of the present invention. FIG. 1B is a sideelevation view illustrating the robot 4. As illustrated in FIG. 1A andFIG. 1B, the robot 4 includes a body unit 41, a head unit 42, a leg unit43L, a leg unit 43R, an arm unit 44L, an arm unit 44R, and a storageunit 45. The head unit 42, the leg unit 43L, the leg unit 43R, the armunit 44L, and the arm unit 44R are movable units, and movably connectedto the body unit 41. The storage unit 45 is attached to the body unit 41in a style of carrying a basket on one's back. The body unit 41 includesa speaker 140L and a speaker 140R. The speaker 140L and a speaker 140Rare voice output units.

FIG. 2 is a block diagram illustrating a configuration of the robot 4.As illustrated in FIG. 2, the robot 4 includes a control unit 100, avoice generating unit 110, a head control unit 120, an arm control unit130L, an arm control unit 130R, a voice output unit 140L, a voice outputunit 140R, a leg control unit 150L, and a leg control unit 150R. Thecontrol unit 100 is a driving control unit. The voice generating unit110 is a voice generating unit. The voice output unit 140L and the voiceoutput unit 140R are voice output units.

The head control unit 120 is disposed in the head unit 42 or at an upperportion of the body unit 41. The head control unit 120 controls anoperation of the head unit 42 in a direction of a pitch axis, which is avertical direction, and in a direction of a yaw axis, which is ahorizontal direction, based on a control signal from the control unit100. By this control, a bearing of the head unit 42 to the body unit 41can be changed in the direction of the pitch axis and in the directionof the yaw axis. Then, the head unit 42 can be shaken from side to sideand up and down.

The leg control unit 150L is disposed in the leg unit 43L. The legcontrol unit 150R is disposed in the leg unit 43R. The leg control unit150L and the leg control unit 150R control an operation such as atwo-legged walking based on the control signal from the control unit100. The arm control unit 130L is disposed in the arm unit 44L. The armcontrol unit 130R is disposed in the arm unit 44R. The arm control unit130L and the arm control unit 130R control an operation of the arm unit44L and the arm unit 44R during the two-legged walking based on thecontrol signal from the control unit 100.

The control unit 100 is disposed in the storage unit 45. The controlunit 100 outputs the control signal to the head control unit 120, theleg control unit 150L, the leg control unit 150R, the arm control unit130L, and the arm control unit 130R, and controls the operation of thehead unit 42, the leg unit 43L, the leg unit 43R, the arm unit 44L, andthe arm unit 44R. The control unit 100 outputs information, whichrepresents the bearing of the head unit 42 to the body unit 41, to thevoice generating unit 110. The information that represents the bearingof the head unit 42 to the body unit 41 is referred to as head unitbearing information.

If the control unit 100 outputs the information, which represents thebearing of the head unit 42 to the body unit 41 after a change of thebearing or a control by the control unit 100, to the head control unit120 as control information, then the control information is output tothe voice generating unit 110 as the head unit bearing information. Ifthe control unit 100 outputs the information, which represents avariation of the bearing of the head unit 42 to the body unit 41 betweenthe present condition and the condition after the change of the bearingor the control by the control unit 100, to the head control unit 120 ascontrol information, then the bearing of the head unit 42 to the bodyunit 41 after the change of the bearing or the control by the controlunit 100 is calculated, and the result of the calculation is output tothe voice generating unit 110 as the head unit bearing information.

The voice generating unit 110 is disposed in the storage unit 45 andincludes a voice signal generating unit 112 and a voice signalcorrection unit 114. The voice signal generating unit 112 generates avoice signal corresponding to a prescribed voice. The voice signalgenerating unit 112 outputs the voice signal, which has been generated,to the voice signal correction unit 114. The prescribed voice is such asthe voice corresponding to a language that is designated from outside,for example, by an operator of the robot 4, the voice corresponding to aresult of a prescribed determination process that is selected based onan order from outside, and the voice corresponding to a detection resultof various sensors that the robot 4 includes, for example, the sensorfor detecting obstacles. The robot 4 can output the voice while movingthe head unit 42.

The voice signal correction unit 114 receives the voice signal from thevoice signal generating unit 112. The voice signal correction unit 114receives the head unit bearing information from the control unit 100.The voice signal correction unit 114 corrects the voice signal, whichhas been received from the voice signal generating unit 112, based onthe head unit bearing information, which has been received from thecontrol unit 100.

Specifically, the voice signal correction unit 114 receives the headunit bearing information that includes an angle showing the bearing ofthe head unit 42 in the direction of the pitch axis and an angle showingthe bearing of the head unit 42 in the direction of the yaw axis.Concerning the bearing of the head unit 42 in the direction of the pitchaxis, the voice signal correction unit 114 corrects the voice signal,which has been received from the voice signal generating unit 112, byusing a vocal tract filter that is based on a vocal tract model. If thebearing of the head unit 42 varies in the direction of the pitch axis,then a shape of the vocal tract varies and a spectral envelope of thevoice signal varies. Concerning the bearing of the head unit 42 in thedirection of the yaw axis, the voice signal correction unit 114 correctsa left-right ratio of an output level of the voice signal that is outputto the voice output unit 140L and the voice output unit 140R. If thebearing of the head unit 42 varies in the direction of the yaw axis,then the shape of the vocal tract does not change and adjusting theleft-right ratio of the output level of the voice signal is sufficient.The vocal tract filter based on the vocal tract model, the left-rightratio of the output level of the voice signal, the correction based onthe bearing of the head unit 42 in the direction of the pitch axis, andthe correction based on the bearing of the head unit 42 in the directionof the yaw axis will be described below.

The voice signal correction unit 114 outputs the voice signal that hasbeen corrected or the voice signal from the voice signal generating unit112 based on the head unit bearing information to the voice output unit140L and the voice output unit 140R.

The voice output unit 140L and the voice output unit 140R are disposedin the body unit 41, as described above. The voice output unit 140L andthe voice output unit 140R receives the voice signal that has beengenerated by the voice generating unit 110 to output a voice to theexterior. The voice signal has been generated by the voice signalgenerating unit 112 or corrected by the voice signal correction unit114.

Details of the voice signal correction unit 114 will be described below.FIG. 3A, FIG. 3B and FIG. 3C are graphs explaining a content related tothe correction by the voice signal correction unit 114. FIG. 4 is a viewexplaining the correction by the voice signal correction unit 114.

Description of the Vocal Tract Filter Based on the Vocal Tract Model

The vocal tract filter is modeled as H(θ_(p)), while θ_(p) is an angleof the head unit 42 in the direction of the pitch axis. In the preferredembodiment of the present invention, the vocal tract filter H(θ_(p)) ismodeled by examining the voice of a man. Specifically, the head of anexaminee is varied (by 10 degrees) between 50 degrees in a downwarddirection and 50 degrees in an upward direction, and each voicecorresponding to each pitch angle θ_(p) is recorded having the samevolume. The recording is performed in an anechoic room by using aclose-talking microphone. As a result, the vocal tract filter H(θ_(p))is modeled. More specifically, a sweep sound for 10 seconds that is madeby producing a vowel “a” and has a basic frequency between 201 Hz and523 Hz is recorded. Next, the voice signal of the recorded voice isanalyzed by using one-third octave-band analysis, and a sound pressurelevel ratio is calculated by using a point of each frequency band whichpitch angle is 0 degrees as a reference point.

The frequency band of the voice signal that is corrected based on thepitch angle θ_(p) is the frequency band in which the sound pressurelevel varies significantly based on the variation of the pitch angleθ_(p). Specifically, three frequency bands i.e. 500 Hz, between 800 Hzand 1,000 Hz, and between 2,500 Hz and 4,000 Hz are used in thefrequency bands. In these three frequency bands, the sound pressurelevel varies significantly based on the variation of the pitch angleθ_(p) as illustrated in FIG. 3A. The frequency band includes formants ofalmost all of the vowels.

The horizontal axis of FIG. 3A represents the pitch angle θ_(p) and “Up”represents the upward direction and “Down” represents the downwarddirection. The vertical axis of FIG. 3A represents the sound pressureratio corresponding to each pitch angle θ_(p), which is calculated byusing a point of each frequency band which pitch angle is 0 degrees as areference point, that is, a gain g^(P) _(i, θ) dB. As illustrated inFIG. 3A, the gain g^(P) _(i, θ) is large when the examinee turns up andis small when the examinee turns down. If the examinee is a woman, theresult is the same.

Description of the Left-Right Ratio of the Output Level of the VoiceSignal

The correction of the left-right ratio of the output level of the voicesignal based on the yaw angle θ_(y) is performed by using a modelillustrated in FIG. 3B. FIG. 3B is a graph illustrating the soundpressure ratio based on the yaw angle θ_(y). The horizontal axis of FIG.3B represents the yaw angle θ_(y) and the unit is degree. A minus valueof the yaw angle represents a right direction and a plus value of theyaw angle represents a left direction. The vertical axis of FIG. 3Brepresents the ratio of the difference between the sound pressure levelof the left channel and the sound pressure level of the right channel,which is calculated by using the difference between the sound pressurelevel of the left channel and the sound pressure of the right channelwhen the yaw angle is zero as the reference point, that is a gain g^(y)_(L, θ) dB. In FIG. 3B, theoretical values and measured values areillustrated. In the preferred embodiment of the present invention, themeasured values, which are more affected by the variation of the yawangle θ_(y), are used so that the variation of the direction of the facecan be represented clearly.

The measurement value illustrated in FIG. 3B can be acquired bymeasuring an impulse response of each microphone “mic.” in the anechoicroom as illustrated in FIG. 3C. The yaw angle θ_(y) illustrated in FIG.3C is set to 0 degrees at the center portion that is in a direction of adashed line and the left direction represents a plus value of the yawangle to be consistent with FIG. 3B.

Correction Based on the Bearing in the Direction of the Pitch Axis andthe Yaw Axis

The voice signal correction unit 114 corrects the voice signal, which isreceived from the voice signal generating unit 112, that is an inputvoice signal x(t) based on the pitch angle θ_(p) of the head unit 42 andthen based on the yaw angle θ_(y), of the head unit 42.

First, for correction based on the pitch angle θ_(p), the voice signalcorrection unit 114 resolves the input voice signal x(t) into aθ_(p)-dependent element x_(i)(t), which depends on the pitch angleθ_(p), and a θ_(p)-independent element x_(NULL)(t), which does notdepend on the pitch angle θ_(p). Here, ‘i’ of the θ_(p)-dependentelement x_(i)(t) represents an index of the frequency band to becorrected. The input voice signal x₁(t) is 500 Hz, the input voicesignal x₂(t) is between 800 Hz and 1,000 Hz, and the input voice signalx₃(t) is between 2,500 Hz and 4,000 Hz.

Specifically, the voice signal correction unit 114 calculates theθ_(p)-dependent element x_(i)(t) based on the equation (1) andcalculates the θ_(p)-independent element x_(NULL)(t) based on theequation (2).

x _(i)(t)=(x*h _(i))(t)  (1)

x _(NULL)(t)=(x*h _(NULL))(t)  (2)

Here, * represents a convolution operation. In the equation (1), h_(i)represents a band pass filter that transmits the θ_(p)-dependent elementx_(i)(t) that includes the frequency bands of 500 Hz, between 800 Hz and1,000 Hz, and between 2,500 Hz and 4,000 Hz. Also x_(NULL)(t) is equalto the input voice signal x(t) minus the θ_(p)-dependent elementx_(i)(t). The gain of the frequency response corresponding to h_(NULL)is zero at the frequency of 500 Hz, between 800 Hz and 1,000 Hz, andbetween 2,500 Hz and 4,000 Hz. The gain of the frequency responsecorresponding to h_(NULL) is 1 at the center frequency of one-thirdoctave-band except the frequency of 500 Hz, between 800 Hz and 1,000 Hz,and between 2,500 Hz and 4,000 Hz.

Next, concerning the θ_(p)-dependent element x_(i)(t), the voice signalcorrection unit 114 calculates a gain g^(p) _(i)(t) of the i-thfrequency band at the pitch angle θ_(p)(t) based on the equation (3).

$\begin{matrix}{{g_{i}^{p}(t)} = \frac{{g_{i,\theta_{m}}^{p}\left( {\theta_{m + 1} - {\theta_{p}(t)}} \right)} + {g_{i,\theta_{m + 1}}^{p}\left( {{\theta_{p}(t)} - \theta_{m}} \right)}}{10}} & (3)\end{matrix}$

In the equation (3), the angle θ_(m) and the angle θ_(m+1) are based onthe pitch angle θ_(p)(t), which represents the bearing of the head unit42 in the direction of the pitch axis, that are included in the headunit bearing information received from the control unit 100.Specifically, the angle θ_(m) and the angle θ_(m+1) are calculated fromthe pitch angle θ_(p)(t) based on the equations (4) and (5).

θ_(m+1)=(└θ_(p)(t)/10┘+1)×10  (4)

θ_(m)=(└θ_(p)(t)/10┘)×10  (5)

Here, └ ┘ represents a floor function. For example, if θ_(p)(t)=35degrees, then θ_(m+1)=40 degrees and the angle θ_(m)=30 degrees.

Concerning the θ_(p)-dependent element x_(i)(t), the voice signalcorrection unit 114 linearly-interpolates and amplifies a spectralenvelope model corresponding to the gain of each pitch angle θ_(p)(t) ofFIG. 3A with dB by 10 degrees as shown in the equations (4) and (5). Thespectral envelope model is shown as A and B of FIG. 4.

Next, the voice signal correction unit 114 amplifies the θ_(p)-dependentelement x_(i)(t) based on the equation (6).

$\begin{matrix}{{x_{i,g}(t)} = {{x_{i}(t)} \times 10^{\frac{g_{i}^{p}{(t)}}{10}}}} & (6)\end{matrix}$

Next, the voice signal correction unit 114 synthesizes theθ_(p)-dependent element x_(i)(t) and the θ_(p)-independent elementx_(NULL)(t) based on the equation (7) to calculate a monaural signalx_(p) that is corrected based on the pitch angle θ_(p)(t).

$\begin{matrix}{{x_{p}(t)} = {{x_{NULL}(t)} + {\sum\limits_{i = 1}^{3}{x_{i,g}(t)}}}} & (7)\end{matrix}$

As described above, the voice signal correction unit 114 corrects thevoice signal x(t), which has been generated by the voice signalgenerating unit 112, based on the pitch angle θ_(p), which representsthe bearing of the head unit 42 in the direction of the pitch axis, byusing the vocal tract filter of the equations (1), (2), . . . and (7).The vocal tract filter is in the time domain and made of the vocal tractfilter H(θ_(p)) that is represented in the frequency domain.

Next, the voice signal correction unit 114 generates a stereo signalx_(ste) from the monaural signal x_(p) so as to correct the voice signalbased on the yaw angle θ_(y). The stereo signal x_(ste) includes a leftchannel signal x_(L)(t) and a right channel signal x_(R)(t).

Next, the voice signal correction unit 114 calculates a gain g^(P)_(L)(t:θ_(y)(t)) of the left channel signal x_(L)(t) corresponding tothe yaw angle θ_(y) based on the equation (8). That is, the voice signalcorrection unit 114 corrects the output level ratio between the leftchannel signal x_(L)(t) and the right channel signal x_(R)(t) based onthe bearing of the head unit 42 in the direction of the yaw axis.

$\begin{matrix}{{g_{L}^{y}\left( {t:{\theta_{y}(t)}} \right)} = \frac{{g_{\theta_{n}}^{y}\left( {\theta_{n + 1} - {\theta_{y}(t)}} \right)} + {g_{\theta_{n + 1}}^{y}\left( {{\theta_{y}(t)} - \theta_{n}} \right)}}{10}} & (8)\end{matrix}$

In the equation (8), the angle θ_(n) and the angle θ_(n+1) are based onthe yaw angle θ_(y)(t) that represents the bearing of the head unit 42in the direction of the yaw axis which is included in the head unitbearing information received from the control unit 100. Specifically,the angle θ_(n) and the angle θ_(n+1) are calculated by the equations(9) and (10) based on the yaw angle θ_(y)(t).

θ_(n+1)=(└θ_(y)(t)/10┘+1)×10  (9)

θ_(n)=(└θ_(y)(t)/10┘)×10  (10)

Here, └ ┘ represents the floor function. For example, if θ_(y)(t)=35degrees, then θ_(n+1)=40 degrees and the angle θ_(n)=30 degrees.

The gain of the left channel signal x_(L)(t) and the gain of the rightchannel signal x_(R)(t) are symmetric as shown in the equation (11).Therefore, the voice signal correction unit 114 calculates a gain g^(P)_(R)(t:θ_(y)(t)) of the right channel signal x_(R)(t) corresponding tothe yaw angle θ_(y)(t).

g _(R) ^(y)(t:θ _(y)(t))=g _(L) ^(y)(t:−θ _(y)(t))  (11)

That is, the voice signal correction unit 114 linearly-interpolates andamplifies a spectral envelope model corresponding to the gain of eachyaw angle θ_(y)(t) of FIG. 3C by 10 degrees as shown in the equations(9) and (10). The spectral envelope model is shown as C of FIG. 4.

The voice signal correction unit 114 amplifies the left channel signalx_(L)(t) based on the equation (12) to generate a left channel outputvoice signal x′_(L)(t), and outputs the left channel output voice signalx′_(L)(t) to the voice output unit 140L. The voice signal correctionunit 114 amplifies the right channel signal x_(R)(t) based on theequation (13) to generate a right channel output voice signal x′_(R)(t),and outputs the right channel output voice signal x′_(R)(t) to the voiceoutput unit 140R.

$\begin{matrix}{{x_{L}^{\prime}(t)} = {{x_{L}(t)} \times 10^{\frac{g_{L}^{p}{(t)}}{10}}}} & (12) \\{{x_{R}^{\prime}(t)} = {{x_{R}(t)} \times 10^{\frac{g_{R}^{p}{(t)}}{10}}}} & (13)\end{matrix}$

As described above, the voice signal correction unit 114 corrects theleft channel signal x_(L)(t) and the right channel signal x_(R)(t) togenerate the left channel output voice signal x′_(L)(t) and the rightchannel output voice signal x′_(R)(t) based on the yaw angle θ_(y)(t)that represents the bearing of the head unit 42 in the direction of theyaw axis. That is, the voice signal correction unit 114 corrects theoutput level ratio of the left channel signal x_(L)(t) and the rightchannel signal x_(R)(t).

As described above, in the preferred embodiment of the presentinvention, the voice generated by the voice generating unit is notoutput from the voice output unit as it is. The voice generated by thevoice generating unit is corrected based on the bearing of the movableunit and then output from the voice output unit. Therefore, the robotcan output a natural sounding voice, which does not seem strange topeople, based on the bearing of the movable unit. The voice is varied byimitating the variation of the voice of a man. The voice is varied basedon the bearing of the head unit 42 not only in the vertical directionbut also in the horizontal direction. Therefore, the robot can output amore natural sounding voice.

The voice signal is corrected based on the bearing in the direction ofthe pitch axis by limiting the frequency of the correction target to aprescribed frequency based on an experimental result. Therefore, theamount of the calculation in performing the correction can be reducedeffectively.

In the preferred embodiment of the present invention described above,the control unit 100 outputs the head unit bearing information to thevoice signal correction unit 114. That is, the voice signal correctionunit 114 receives the head unit bearing information from the controlunit 100. The head unit bearing information represents the bearing ofthe head unit 42 to the body unit 41. The voice signal correction unit114 refers to the head unit bearing information when correcting thevoice signal. But the way of the voice signal correction unit 114receiving the head unit bearing information is not limited to the aboveway. For example, the robot 1 may include a measurement unit, which isnot illustrated in the figure, that measures the bearing of the headunit 42 to the body unit 41, and the voice signal correction unit 114may use the measurement result of the measurement unit as the head unitbearing information.

In the preferred embodiment of the present invention described above,the voice signal correction unit 114 corrects the voice signal based onthe head unit bearing information. However, the method of the voicesignal correction unit 114 correcting the voice signal is not limited tothe above described method. For example, the voice signal correctionunit 114 may correct the voice signal based on information including thebearing of the leg unit 43L, the leg unit 43R, the arm unit 44L, and thearm unit 44R to the body unit 41.

A program that executes various processing of the robot 4 in accordancewith the preferred embodiment of the present invention may be stored ina computer-readable recording medium. A computer system may read andexecute the program that is stored in the recording medium to performthe various processing described above in accordance with the robot 4 ofthe preferred embodiment of the present invention. The computer systemmay include an OS or hardware such as peripheral device etc. Also, thecomputer system may employ a WWW (World Wide Web) system. With such anarrangement, the computer system includes a homepage providingcircumstances or homepage display environment.

Further, the computer readable recording medium refers to a writablenonvolatile memory such as a flexible disk, a magneto-optical disk, aROM, or a flash memory, a portable medium such as a CD-ROM, and a memorydevice such as a hard disk incorporated in a computer system.

In addition, the “computer readable recording medium” includes a mediumstoring a program for a predetermined time period, such as a volatilememory (for example, dynamic random access memory (DRAM)) incorporatedin the computer system which becomes a server or a client in a casewhere the program is transmitted via a network such as the Internet, ora communication line such as a telephone line.

Further, the above-mentioned program may be transmitted from thecomputer system which stores the program in the memory device or thelike via a transmission medium, or may be transmitted by a transmittedwave through the transmission medium to another computer system. In thiscase, the “transmission medium” for transmitting the program refers to amedium having a function for transmitting information like a network(communication network) such as the Internet, or a communication line(communication wire) such as a telephone line.

Further, the above-mentioned program may be a program for realizing partof the above-mentioned function. Moreover, there may be used a programthat can realize the above-mentioned function by a combination of aprogram already recorded in the computer system, that is, a differentialfile (differential program).

In the above descriptions of the present invention, the bearing of therobot represents the attitude of the robot. The bearing of the movableunit is equal to the bearing of the robot.

As used herein, the following directional terms “forward, rearward,above, downward, vertical, horizontal, below, and transverse” as well asany other similar directional terms refer to those directions of anapparatus equipped with the present invention. Accordingly, these terms,as utilized to describe the present invention should be interpretedrelative to an apparatus equipped with the present invention.

The term “configured” is used to describe a component, section or partof a device including hardware and/or software that is constructedand/or programmed to carry out the desired function.

Moreover, terms that are expressed as “means-plus function” in theclaims should include any structure that can be utilized to carry outthe function of that part of the present invention.

The terms of degree such as “substantially,” “about,” “nearly”, and“approximately” as used herein mean a reasonable amount of deviation ofthe modified term such that the end result is not significantly changed.For example, these terms can be construed as including a deviation of atleast ±5 percents of the modified term if this deviation would notnegate the meaning of the word it modifies.

While preferred embodiments of the invention have been described andillustrated above, it should be understood that these are exemplary ofthe invention and are not to be considered as limiting. Additions,omissions, substitutions, and other modifications can be made withoutdeparting from the scope of the present invention. Accordingly, theinvention is not to be considered as being limited by the foregoingdescription, and is only limited by the scope of the claims.

1. A robot comprising: a driving control unit configured to control adriving of a movable unit that is connected movably to a body unit; avoice generating unit configured to generate a voice; and a voice outputunit configured to output the voice, which has been generated by thevoice generating unit, wherein the voice generating unit corrects thevoice, which is generated, based on a bearing of the movable unit, whichis controlled by the driving control unit, to the body unit.
 2. Therobot according to claim 1, wherein the movable unit includes a headunit, and the voice generating unit corrects the voice, which isgenerated using a vocal tract filter, based on the bearing in adirection of a pitch axis of the head unit.
 3. The robot according toclaim 1, wherein the movable unit includes a head unit, and the voicegenerating unit corrects a left-right ratio of an output level of thevoice, which is generated, based on the bearing in a direction of a yawaxis of the head unit.
 4. The robot according to claim 2, wherein thevoice generating unit uses the vocal tract filter, which amplifies afrequency band of a signal of the voice, a sound pressure level is basedon a pitch angle that corresponds to the bearing of the head unit in thefrequency band, and the voice generating unit amplifies the frequencyband, which is based on the pitch angle, of the signal of the voice,which is generated, using the vocal tract filter.
 5. The robot accordingto claim 2, wherein the voice generating unit corrects a left-rightratio of an output level of the voice, which is generated, based on thebearing in a direction of a yaw axis of the head unit.
 6. The robotaccording to claim 4, wherein the voice generating unit corrects aleft-right ratio of an output level of the voice, which is generated,based on the bearing in a direction of a yaw axis of the head unit.
 7. Amethod of controlling a robot comprising: controlling of a driving of amovable unit that is connected movably to a body unit; generating of avoice; and outputting of the voice, which has been generated, whereinthe generating of the voice comprises correcting of the voice based on abearing of the movable unit to the body unit.
 8. A program that controlsa robot including a movable unit that is connected movably to a bodyunit, the robot generating and outputting a voice, the programexecuting: a driving control step of controlling a driving of themovable unit; a voice generating step of generating the voice; and avoice output step of outputting the voice, which has been generated bythe voice generating step, wherein the voice generating step correctsthe voice, which is generated, based on a bearing of the movable unit,which is controlled by the driving control step, to the body unit.